1. Field of the Invention
The present invention relates to an electronic equipment utilizing vibration of a vibration motor means for noticing a call signal or alarm, etc., to a bearer of the electronic equipment and, particularly, to a structure of a holding member for supporting the vibration motor.
2. Description of the Related Art
Various electronic equipments, particularly, portable communication equipments such as selective call receivers or portable telephone sets usually notice a call to a bearer thereof by ringing. It has been known, however, that there may be situations such as conference, etc., in which ringing sound is undesirable. In order to make the portable communication device usable in such situation, there is a selective call receiver or a portable telephone set equipped with a vibration generator for noticing a call to a bearer of the receiver or telephone set by vibration. In the selective call receiver, etc., the vibration generator is constructed with a vibration motor having a rotary shaft mounted thereon with an eccentric weight and housed in a casing of the selective call receiver and vibration is generated by driving the vibration motor.
A conventional vibration motor used generally has an outer peripheral portion supported by a metal holding member and is fixed to a printed circuit board provided within a casing of an electronic equipment by soldering, etc., together with the holding member. The holding member for supporting the vibration motor, however, must be formed in advance on the printed circuit board in such a way that the holding member fits the outer periphery of the vibration motor, which causes the receiver to be expensive. Further, since the holding member is fixed directly on the printed circuit board, irregular sound tends to be produced due to resonance of the printed circuit board.
Japanese Patent Application Laid-open No. H8-051286 discloses a vibration motor holding structure in which a holding member formed of rubber or soft plastic material supports an outer periphery of a vibration motor and the holding member is fixed to a casing of an electronic equipment with the holding member being in between inner walls of the casing. Further, Japanese Patent Application Laid-open No. H8-140298 discloses a vibration motor holding structure in which a vibration motor is wrapped with a thin film of silicon rubber and is supported in between ribs formed on an inner wall of a casing of an electronic equipment. These vibration motor holding structures can restrict generation of irregular sound, are inexpensive and can be miniaturized.
However, conventional portable electronic equipments having the above described vibration motor holding structure have a common problem that it is relatively difficult for bearers of them to detect alarming vibration. That is, a bearer of the portable electronic equipment feels vibration noticing a call signal through the casing of the electronic equipment. In the conventional portable electronic equipment, since a source of vibration such as the vibration motor and the holding member, etc., are completely housed in the casing of the equipment, vibration generated by the vibration motor is diffused and is attenuated by the casing. Therefore, the bearer has to feel attenuated vibration at a surface of the casing. Further, since the casing is usually formed of plastic material or metal whose hardness is high and its surface is made smooth in view of the safety of bearer, the surface of the casing of the conventional vibration motor holding structure of the portable electronic equipment is not suitable in effectively transmitting vibration to the bearer.